[Federal Register Volume 61, Number 91 (Thursday, May 9, 1996)]
[Proposed Rules]
[Pages 21146-21148]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 96-11533]



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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 96-CE-16-AD]
RIN 2120-AA64


Airworthiness Directives; Pilatus Britten-Norman Ltd. (formerly 
Britten-Norman) BN-2A and BN2A MK. 111 Series Airplanes

AGENCY: Federal Aviation Administration, DOT.

ACTION: Notice of proposed rulemaking (NPRM).

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SUMMARY: This document proposes to supersede Airworthiness Directive 
(AD) 75-26-15, which currently requires repetitively inspecting the 
aileron mass balance clamp unit attachment for looseness on Pilatus 
Britten-Norman Ltd. (Pilatus Britten-Norman) BN-2A and BN2A MK. 111 
series airplanes, and modifying the aileron and mass balance clamp unit 
if any looseness is found. The Federal Aviation Administration's policy 
on aging commuter-class aircraft is to eliminate or, in certain 
instances, reduce the number of certain repetitive short-interval 
inspections when improved parts or modifications are available. The 
proposed action would retain the repetitive inspections required by AD 
75-26-15, and would require modifying the aileron and mass balance unit 
(at a certain time) as terminating action for the repetitive 
inspections. The actions specified in the proposed AD are intended to 
prevent failure of the aileron mass balance attachment, which could 
result in loss of control of the airplane.

DATES: Comments must be received on or before July 19, 1996.

ADDRESSES: Submit comments on the proposal in triplicate to the Federal 
Aviation Administration (FAA), Central Region, Office of the Assistant 
Chief Counsel, Attention: Rules Docket No. 96-CE-16-AD, Room 1558, 601 
E. 12th Street, Kansas City, Missouri 64106.Comments may be inspected 
at this location between 8 a.m. and 4 p.m., Monday through Friday, 
holidays excepted.
    Service information that applies to the proposed AD may be obtained 
from Pilatus Britten-Norman Limited, Bembridge, Isle of Wight, United 
Kingdom PO35 5PR; telephone 44-1983 872511; facsimile 44-1983 873246. 
This information also may be examined at the Rules Docket at the 
address above.

FOR FURTHER INFORMATION CONTACT: Ms. Dorenda Baker, Program Officer,

[[Page 21147]]

Brussels Aircraft Certification Office, FAA, Europe, Africa, and Middle 
East Office, c/o American Embassy, B-1000 Brussels, Belgium; telephone 
(32 2) 508.2715; facsimile (32 2) 230.6899; or Mr. Jeffrey Morfitt, 
Project Officer, Small Airplane Directorate, Airplane Certification 
Service, FAA, 1201 Walnut, suite 900, Kansas City, Missouri 64106; 
telephone (816) 426-6932; facsimile (816) 426-2169.

SUPPLEMENTARY INFORMATION:

Comments Invited

    Interested persons are invited to participate in the making of the 
proposed rule by submitting such written data, views, or arguments as 
they may desire. Communications should identify the Rules Docket number 
and be submitted in triplicate to the address specified above. All 
communications received on or before the closing date for comments, 
specified above, will be considered before taking action on the 
proposed rule. The proposals contained in this notice may be changed in 
light of the comments received.
    Comments are specifically invited on the overall regulatory, 
economic, environmental, and energy aspects of the proposed rule. All 
comments submitted will be available, both before and after the closing 
date for comments, in the Rules Docket for examination by interested 
persons. A report that summarizes each FAA- public contact concerned 
with the substance of this proposal will be filed in the Rules Docket.
    Commenters wishing the FAA to acknowledge receipt of their comments 
submitted in response to this notice must submit a self-addressed, 
stamped postcard on which the following statement is made: ``Comments 
to Docket No. 96-CE-16-AD.'' The postcard will be date stamped and 
returned to the commenter.

Availability of NPRM's

    Any person may obtain a copy of this NPRM by submitting a request 
to the FAA, Central Region, Office of the Assistant Chief Counsel, 
Attention: Rules Docket No. 96-CE-16-AD, Room 1558, 601 E. 12th Street, 
Kansas City, Missouri 64106.

Discussion

    The FAA has determined that reliance on critical repetitive 
inspections on aging commuter-class airplanes carries an unnecessary 
safety risk when a design change exists that could eliminate or, in 
certain instances, reduce the number of those critical inspections. In 
determining what inspections are critical, the FAA considers (1) the 
safety consequences if the known problem is not detected during the 
inspection; (2) the probability of the problem not being detected 
during the inspection; (3) whether the inspection area is difficult to 
access; and (4) the possibility of damage to an adjacent structure as a 
result of the problem.
    These factors have led the FAA to establish an aging commuter-class 
aircraft policy that requires incorporating a known design change when 
it could replace a critical repetitive inspection. With this policy in 
mind, the FAA conducted a review of existing AD's that apply to Pilatus 
Britten-Norman BN-2A and BN2A MK. 111 series airplanes. Assisting the 
FAA in this review were (1) Pilatus Britten-Norman; (2) the Regional 
Airlines Association (RAA); and (3) several operators of the affected 
airplanes.
    From this review, the FAA has identified AD 75-26-15, Amendment 39-
2464, as one that should be superseded with a new AD that would require 
incorporating a modification that would eliminate the need for short-
interval and critical repetitive inspections. AD 75-26-15 currently 
requires repetitively inspecting the attachment of the aileron mass 
balance clamp unit for looseness on Pilatus Britten-Norman BN-2A and 
BN2A MK. 111 series airplanes, and modifying any aileron and mass 
balance clamp unit where looseness is found. Accomplishment of the 
inspections and modification required by AD 75-26-15 is in accordance 
with Britten-Norman Service Bulletin No. BN-2/SB.67, Issue 1, dated 
October 24, 1973.
    Based on its aging commuter-class aircraft policy and after 
reviewing all available information, the FAA has determined that AD 
action should be taken to eliminate the repetitive short-interval 
inspections required by AD 75-26-15, and to prevent failure of the 
aileron mass balance attachment, which could result in loss of control 
of the airplane.
    Since an unsafe condition has been identified that is likely to 
exist or develop in other Pilatus Britten-Norman BN-2A and BN2A MK. 111 
series airplanes of the same type design, the proposed AD would 
supersede AD75-26-15 with a new AD that would (1) retain the 
requirements of repetitively inspecting the aileron mass balance clamp 
unit attachment for looseness and modifying any aileron and mass 
balance unit immediately where looseness is found; and (2) require 
modifying the aileron and mass balance unit (at a certain time) if not 
previously required. The modification would terminate the need for the 
repetitive inspections of the aileron and mass balance unit attachment. 
Accomplishment of the proposed actions would continue to be in 
accordance with Britten-Norman Service Bulletin No. BN-2/SB.67, Issue 
1, dated October 24, 1973.
    The FAA estimates that 109 airplanes in the U.S. registry would be 
affected by the proposed AD, that would take approximately 10 workhours 
(inspection: 1 workhour; modification: 9 workhours) per airplane to 
accomplish the proposed action, and that the average labor rate is 
approximately $60 an hour. Parts cost approximately $160 per airplane. 
Based on these figures, the total cost impact of the proposed AD on 
U.S. operators is estimated to be $82,840. This figure only takes into 
account the cost of the proposed initial inspection and proposed 
inspection-terminating modification and does not take into account the 
cost of the proposed repetitive inspections. The FAA has no way of 
determining the number of repetitive inspections each of the owners/
operators would incur over the life of the affected airplanes.
    This figure is also based on the assumption that none of the 
affected airplane owners/operators have accomplished the proposed 
modification. This action would eliminate the repetitive inspections 
required by AD 75-26-15. The FAA has no way of determining the 
operational levels of each individual operator of the affected 
airplanes, and subsequently cannot determine the repetitive inspection 
costs that would be eliminated by the proposed action. The FAA 
estimates these costs to be substantial over the long term.
    Pilatus Britten-Norman does not know the number of parts 
distributed to the affected airplane owners/operators. Numerous sets of 
parts were sent out to the owners/operators of the affected airplanes, 
but over the years Pilatus Britten-Norman has not retained these 
records. The company believes that most of the affected airplanes 
already have the proposed inspection-terminating modification 
incorporated.
    The intent of the FAA's aging commuter airplane program is to 
ensure safe operation of commuter-class airplanes that are in 
commercial service without adversely impacting private operators. Of 
the approximately 109 airplanes in the U.S. registry that would be 
affected by the proposed AD, the FAA has determined that approximately 
25 percent are operated in scheduled passenger service by 11 different 
operators. A significant number of the remaining 75percent are operated 
in

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other forms of air transportation such as air cargo and air taxi.
    The proposed action would allow 1,000 hours TIS after the effective 
date of the AD before mandatory accomplishment of the design 
modification. The average utilization of the fleet for those airplanes 
in commercial commuter service is approximately 25 to 50 hours TIS per 
week. Based on these figures, operators of commuter-class airplanes 
involved in commercial operation would have to accomplish the proposed 
modification within 5 to 10 calendar months after the proposed AD would 
become effective. For private owners, who typically operate between 100 
to 200 hours TIS per year, this would allow 5 to 10 years before the 
proposed modification would be mandatory. The time it would take those 
in air cargo/air taxi operations before the proposed action would be 
mandatory is unknown because of the wide variation between each 
airplane used in this service. The exact numbers would fall somewhere 
between the average for commuter operators and private operators.
    The regulations proposed herein would not have substantial direct 
effects on the States, on the relationship between the national 
government and the States, or on the distribution of power and 
responsibilities among the various levels of government. Therefore, in 
accordance with Executive Order 12612, it is determined that this 
proposal would not have sufficient federalism implications to warrant 
the preparation of a Federalism Assessment.
    For the reasons discussed above, I certify that this action (1) is 
not a ``significant regulatory action'' under Executive Order 12866; 
(2) is not a``significant rule'' under DOT Regulatory Policies and 
Procedures (44 FR 11034, February 26, 1979); and (3) if promulgated, 
will not have a significant economic impact, positive or negative, on a 
substantial number of small entities under the criteria of the 
Regulatory Flexibility Act. A copy of the draft regulatory evaluation 
prepared for this action has been placed in the Rules Docket. A copy of 
it may be obtained by contacting the Rules Docket at the location 
provided under the caption ADDRESSES.

List of Subjects in 14 CFR Part 39

    Air transportation, Aircraft, Aviation safety, Safety.

The Proposed Amendment

    Accordingly, pursuant to the authority delegated to me by the 
Administrator, the Federal Aviation Administration proposes to amend 
part 39 of the Federal Aviation Regulations (14 CFR part 39) as 
follows:

PART 39--AIRWORTHINESS DIRECTIVES

    1. The authority citation for part 39 continues to read as follows:

    Authority: 49 U.S.C. 106(g), 40113, 44701.


Sec. 39.13  [Amended]

    2. Section 39.13 is amended by removing Airworthiness Directive 
(AD) 75-26-15, Amendment 39-2464, and by adding a new AD to read as 
follows:

Pilatus Britten-Norman Ltd.: Docket No. 96-CE-16-AD. Supersedes AD 
75-26-15, Amendment 39-2464.

    Applicability: Models BN-2, BN-2A, BN-2A-6, BN-2A-8, BN-2A-2, 
BN-2A-9, BN-2A-3, BN-2A-20, BN-2A-21, BN-2A-26, BN-2A-27, BN2A MK. 
111, BN2A MK. 111-2, and BN2A MK. 111-3 airplanes (all serial 
numbers), certificated in any category.

    Note 1: This AD applies to each airplane identified in the 
preceding applicability provision, regardless of whether it has been 
modified, altered, or repaired in the area subject to the 
requirements of this AD. For airplanes that have been modified, 
altered, or repaired so that the performance of the requirements of 
this AD is affected, the owner/operator must request approval for an 
alternative method of compliance in accordance with paragraph (f) of 
this AD. The request should include an assessment of the effect of 
the modification, alteration, or repair on the unsafe condition 
addressed by this AD; and, if the unsafe condition has not been 
eliminated, the request should include specific proposed actions to 
address it.

    Compliance: Required as indicated in the body of this AD, unless 
already accomplished.
    To prevent failure of the aileron mass balance attachment, which 
could result in loss of control of the airplane, accomplish the 
following:
    (a) Prior to the first flight of each day after the effective 
date of this AD (see NOTE 2 of this AD), inspect the attachment of 
the aileron mass balance clamp unit for looseness in accordance with 
the ``Inspection'' section of Britten-Norman Service Bulletin (SB) 
No. BN-2/SB.67, Issue 1, dated October 24, 1973.

    Note 2: The ``prior to first flight of each day after the 
effective date of this AD'' compliance time required by paragraph 
(a) of this AD is exactly the same as required by AD 75-26-15 
(superseded by this AD).

    (b) If a loose attachment of the aileron mass balance clamp unit 
is found during any of the inspections required by this AD, prior to 
further flight, modify the aileron and mass balance clamp unit in 
accordance with the ``b. Sequence of Operations'' section of 
Britten-Norman SB No. BN-2/SB.67, Issue 1, dated October 24, 1973.
    (c) Within the next 1,000 hours time-in-service after the 
effective date of this AD, unless already accomplished as specified 
and required by paragraph (b) of this AD, modify the aileron and 
mass balance clamp unit in accordance with the ``b. Sequence of 
Operations'' section of Britten-Norman SB No. BN-2/SB.67, Issue 1, 
dated October 24, 1973.
    (d) Accomplishing the modification required by paragraph (b) or 
(c) of this AD is considered terminating action for the repetitive 
inspection requirement of this AD.
    (e) Special flight permits may be issued in accordance with 
sections 21.197 and 21.199 of the Federal Aviation Regulations (14 
CFR 21.197 and 21.199) to operate the airplane to a location where 
the requirements of this AD can be accomplished.
    (f) An alternative method of compliance or adjustment of the 
initial or repetitive compliance times that provides an equivalent 
level of safety may be approved by the Manager, Brussels Aircraft 
Certification Office (ACO), Europe, Africa, Middle East office, FAA, 
c/o American Embassy, 1000 Brussels, Belgium. The request should be 
forwarded through an appropriate FAA Maintenance Inspector, who may 
add comments and then send it to the Manager, Brussels ACO.

    Note 3: Information concerning the existence of approved 
alternative methods of compliance with this AD, if any, may be 
obtained from the Brussels ACO.

    Note 4: Alternative methods of compliance approved in accordance 
with AD 75-26-15 (superseded by this action) are not considered 
approved as alternative methods of compliance with this AD.

    (g) All persons affected by this directive may obtain copies of 
the document referred to herein upon request to Pilatus Britten-
Norman Limited, Bembridge, Isle of Wight, United Kingdom PO35 5PR; 
or may examine this document at the FAA, Central Region, Office of 
the Assistant Chief Counsel, Room 1558, 601 E. 12th Street, Kansas 
City, Missouri 64106.
    (h) This amendment supersedes AD 75-26-15, Amendment 39-2464.

    Issued in Kansas City, Missouri, on May 2, 1996.
Bobby W. Sexton,
Acting Manager, Small Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 96-11533 Filed 5-8-96; 8:45 am]
BILLING CODE 4910-13-U